cltjley



1. P. CLU'L'EY. HEADLIGHT. APPLICATION FILED MAR.4, I918.

1,399,378. Patented Dec. 6, 1921.

usrrsasrarss earner orrlcn.

7 JOHN P. CLULEY, OF CHICAGO, ILLINOIS.

HEADLIGHT.

. Application filed March 4, 1918. Serial No. 220,192.

This invention relates to improvements in.

incandescent lamps and more particularly to an incandescent lamp adapted for use in coni nection with headlights, the same being designed primarily to eliminate the objectionable glare from such lights.

In the standard commercial incandescent lamps of the type now commonly used in automobile headlights, the light source consists of a filament of resistance material either V- shaped or in the form of a helix. In either of these standard constructions a portion of the filament must necessarily coincide with the focal point of the reflector, in order to produce the desirable horizontal and parallel rays. It is obvious, however, that owing to the length and relative arrangement of said filament that certain other portions thereof will be positioned either forward or backward of said focal point; that portion which is disposedinadvance of the focal point producing convergent reflected rays while the portion which lies in back of said point produces divergent reflected rays. Thus the rays emanating from the light source of either of the above types will be projected forwardly by the parabola in a beam which comprises. intermingled horizontal, divergent and convergcntlight rays so that to treat or bend one set of such rays, in order to eliminate the glaring effect of the beam as a whole, is impossible without a corresponding impairment or derangement of the other rays.

Another source of glare is also to be found in the standard lamps above described. I The bulbs of these lamps are spherical in shape and in the manufacture of the same it has been found impossible to position the filament in the direct center of the bulb with any degree of certainty. In other words, the filament in the finished lamp is either forward of or in rear of the center of Specification of Letters Patent.

Patented Dec. 6, 1921.

the bulb with the result that a secondary image or light source is set up in the bulb by the reflection and'concentration of the rays which emanate from the filament and Wl'llCll are reflected back by the inner surface of the forepart of the spherical bulb. If thefilament is in arrears of the center of the bulb, the secondary image will be cast 1n advance thereof and vice versa, and it is, therefore, impossible to position such a lamp within a reflector so as to eliminate the glare, because either the filament or the secondary light source or both will be offset from the focal point of the reflector in whatever position the lamp may be placed.

One object of the present invention therefore is to provide a light source which will produce a beam of reflected light devoid of a multiplicity of upward and downward mixed convergent and divergent rays whereby the objectionable glare of the beam is eliminated.

Another object of the invention resides in the provision ofa light source or lamp havas regards said upward and downward'rays.

A further object of the invention is to provide an incandescent lamp of the type described, the fore part of the bulb of which is of such shape that the rays which emanate from the filament therein and strike said part will be reflected as divergent rays rather than convergent and concentrated rays. whereby the objectionable secondary image of the standard spherical bulb is eliminated.

Another object of the invention is to provide means whereby said lamp maybe quickly and easily positioned in any automobile headlight of standard construction and whereby the same may be adjusted either before or after it has been positioned therein.

Other objects and advantages will be apparent from the following description taken ameter.

the imfilament 2, base 3 and screw-threaded stem el. The bulb 1 is irregular in shape, the part in rear of the filament 2 thereof belng of substantially hemispherical design, while the forepart thereof is of such shape that rays emanating from the filament and contacting with said part will be reflected back as divergent rays rather than convergent and concentratedrays as is the case in the lamps now commonly employed. The filament .2 is preferably in the form of a helix, the same, however, being of very small di- The filament is preferably placed transversely within the bulb at substantially right angles to the base 8, as shown more clearly in Fig. 2 of the drawings, the same being connected across the terminals 5 in the usual manner.

Means is provided whereby the lamp will be of substantially universal application. In other words, said means is provided in order that the lamp may be quickly and easily mounted within a reflector of any headlight of standard construction and whereby said lamp may be adjusted to its proper relative position either before or after the same has been positioned within the reflector. The means which renders this universal adaptation possible comprises an outer sleeve 6 and an inner sleeve 7, each of said sleeves being provided with suitable collars 8 and 9 respectively, at their forward ends, as shown, the collarS carried by the outer sleeve being adapted to project slightly beyond the periphery of the collar 9, substantially as shown, and is preferably provided with knurling or some other suitable gripping means.

The inner sleeve 7 is designed to fit loosely within the outer sleeve 6 and to be held therein against longitudinal movements relative thereto by a suitable flange 10, struck up on the inner end of said sleeve 7. This assembling of the two sleeves does not, however, prevent relative rotary movements or adjustments. When the two sleeves are assembled, as just described, the collars 8 and 9 are adjacent to and in contact with each other, as shown in Fig. 1. The inner sleeve 7 is screw-threaded, as illustrated at 11 and is designed to receive the screw-threaded stem 1 of the lamp. In the inner end of the sleeve 7 is positioned a suitable plug 7 of some suitable insulating material through which extends a suitable conductor 13 with which the inner end of the stem 1 of the lamp is designed to make contact. The other end of the conductor 13 terminates on the outer face of the plug 7 and is attached to a contact shoe 13 mounted thereon. Another contact shoe 1 1 is also carried on the outer face of the plug 7 a and is provided with a depending lug 14- which overhangs the side of said plug as shown and which is designed to make contact with the sleeve 7 when the plug is in place. From this, it will be noted that in the event a single contact socket is encountered, the circuit is completed through the conductor 18 independently of the shoes 13 and 14 whereas if a double contact socket should be encountered, the circuit is completed through the shoe 13, conductor 13, through the filament of the lamp, back through the stem thereof, into the sleeve 7 and then back to the source through the lug 1 1 and shoe 14:. In this manner an adapter is provided whereby the lamp may be used without altering the same, with either single or double contact. sockets.

The collar 9 which is integral with the inner sleeve 7, is provided with a suitable set screw 16 which isv adapted to extend into contact with the screw-threaded stem 4 of the lamp when'the same has been positioned therein. The outer sleeve 6 is provided with a plurality of radial lugs 17 preferably struck up integral therewith,

which lugs are adapted for engagement with the ordinary bayonet joint 15 of the headlight socket 15,, thus enabling the lamp to be readily and quickly positioned therein, after assembly, in the same manner in which the lamps now used are positioned. A

After the lamp has been screwed into the inner sleeve 7 of the adjustable adapter, the set screw 16 carried by the collar 9 is screwed down into contact with the stem 1- thereby holding the lamp firmly in place and against accidental displacement.

After the lamp has thus been mounted in the inner sleeve and made fast therewith, it may be readily andquickly inserted in the socket as shown more clearly in Fig. 5 and retained therein by the engagement of the radial lugs 17 with the bayonet joint 15 it being preferred to grasp the knurled collar 8 in positioning said lamp within the socket. The socket shown in Fig. 5, is one of the ordinary single contact type, the contact being urged outwardly by a spring in the usual manner, substantially as shown. It will be noted that this spring-pressed contact member of the socket. when the lamp is in place, bears against the plug 7 which this friction" between the flange '10 of the sleeve 7 and the inner edge of sleeve 6 is sufli cient to prevent any accidental displacement of said sleeves, it permits of the inner sleeve 7 being rotated within the outer sleeve 6 for purposes of adjustment after the lamp has been inserted in the socket. In other words, it is preferred to make the sleeve 7 fast with the stem of the lamp before insertion and to make the adjustments in order to present the filament 2 in its proper relative position with respect to the reflector and its focal point after insertion. It will be noted that after the various parts have been assembled as above described and the lamp inserted in the socket and adjusted, that the entire structure is maintained firm and rigid at all times.

With the standard spherical bulb, it is impossible to produce a light without glare unless the filament is placed substantially in the center of said bulb, in which event the reflections from the inner surface thereof would cause the concentration of the rays on the filament itself, thus eliminating the secondary image. In other words, the filament and the secondary image would exactly coincide. This, however, is apractical impossibility owing to the method of manufacturing incandescent lamps. In other words, as above pointed out, the filament of a lamp cannot, with any degree of certainty, be placed in the direct center of the bulb. Hence, deviations are bound to occur accom panied by the objectionable result-s, above pointed out.

With the lamp herein described, however, it is clear that there can be no secondary image regardless of the position of the filament within its bulb owing to the peculiar shape of the forepart thereof, the inner surface of which reflects the rays emanating from the light source as divergent rays as illustrated diagrammatically at 30 and 31 in Fig. 6. It will be noted that the forepart of the bulb is of such shape that none of the rays emanating from the filament will be reflected thereby as convergent rays.

It is also believed to be apparent from the foregoing that in the use of the lamps of the standard types above described, a mass of divergent, convergent and horizontal rays is bound to result, even assuming the filament to be placed centrally within the bulb, because of the practical impossibility of positioning the filament Within the focal point of the reflector, owing to the length, shape and relative arrangement of said filament. Accordingly, the light given off will be glaring unless some auxiliary device is provided to eliminate it. With the present lamp, however, wherein a, substantially straight transverse line filament is used,it is obvious that when the same is placed substantially horizontally within av reflector as shown in Fig. 6, that asv regards the rays 32 which emanate from the light, source in an upwardly or downwardly direction, the said filament is substantially a point, which point may readily be made to coincide entirely with the focal oint of the reflector. It is believed to be c ear that when the filament 2 is so positioned, these rays 32, which it will be notedare reflected by the top and bottom surfaces of the parabola only, will be projected forwardly in substantially horizontal and parallel planes, the only direct rays of light emanating from the llght source 2 which will be projected forwardly as mixed paral-.

lel, convergent and divergent rays being those which are reflected by the sides of the reflector. These convergent and divergent rays thus projected, however, can impart no glare to the beam of light as far as an observer in front of the light is concerned by reason of the fact that such rays will be below the line of vision. However, owing to the widely divergent indirect rays of light 83 reflected back against the parabola by the fore part of the lamp bulb herein described, the beam of light projected forwardly will not be entirely free from upwardly projected divergent rays because all of such indirect rays will be reflected in widely divergent planes as illustrated in Fig. 6. These reflected indirect rays, however, it has been found are not glare rays, first, because they have become weakened to a certain degree by double reflection and second, because they are widely diffused. Hence, these rays are not objectionable. On the contrary, they are highly desirable because, as is well known, a certain amount of non-glaring widely diffused light is essential for road lighting purposes. Accordingly, a very desirable and highly efiicient headlight entirely free from glare is obtained by the use of the present improvements.

It is not intended to restrict the present invention to the detailed construction and combination of parts herein illustrated and described except where limitations appear in the appended claims.

.Having thus described my invention, what I claim as new and desire to secure by Letters Patent of the United States is 1. The combination with a parabolic reflector, of a substantially straight line light source horizontally positioned at the focal point of said reflector, a transparent envelop for said light source the fore part of which is of such a shape that direct rays from the light source reflected thereby are divergent, and means for adjusting said light sdufce Within said rfiecfdr to posi- @1011 said light soufce at the focal point of said reflector without disturbing the horizontal position of said light source.

2. The combination with a parabolic reflector Of a light source of small 'conc'entrat ed s'etio'n, a trans arent envel'op for said light source the fore part of which is shaped to reflect direct rays away from the Coil-Geh- In witn'ss Where'bfll hereunto subsefi a 15 my name this 19th thy of February, A. D. 1918. .7 7 JOHN P. CLULEY. 

